It is generally known to provide multilayer structures that may be utilized as heat sealant structures to form packages for products, such as, for example, flowable products. Many multilayer structures are known having a variety of properties, such as heat sealability, flowability, and the like.
Packages for enclosing products are typically made by forming a thermoplastic polymeric structure into a shape to accommodate the product, placing another thermoplastic polymeric structure over the product and then heat sealing the structures together to maintain the product within the two structures. Packages for products may also be made by forming a thermoplastic polymeric structure into a pouch, or otherwise folding a thermoplastic polymeric structure over itself, filling the structure with a product, and then heat sealing the structure closed. The packages made from the above, however, can have problems in their heat-sealing and tearability properties. These issues are especially problematic if the package, containing a flowable product, is intended to be opened by a consumer wherein a combination of good seal and good tear properties are desired and necessary.
Certain products, such as, for example, condiments, require thermoplastic multilayer structures to form relatively small packages. For example, it is well known that catsup, mustard and other like condiments are packaged in individual serving sizes, especially at fast-food restaurants or the like.
Typical packages for flowable products, such as condiments, have walls made from multilayer thermoplastic structures that are not typically easily torn, such that the product may not be easily retrieved or otherwise utilized from the package. Therefore, packages may be difficult to open by young children, the aged or infirm, and other like individuals having reduced ability to cause the structures to tear. The walls of a package for flowable products, such as, for example, condiments or the like, should be easily tearable without also causing the product to be spilled or otherwise lost.
Moreover, typical packages for flowable products, such as, for example, condiments and/or wrinkles or the like, do not provide good seals when heat sealed because of contaminants and/or wrinkles that may be present within the heat seal zone. Typically, condiment packaging is made by a known process called vertical form, fill and seal (VFFS), which comprises bringing together two thermoplastic polymeric structures in face-to-face contact and wrapping the structures around product filling tubes. The structures are heat sealed on opposite sides of the product filling tubes in the machine direction to form side seals of the condiment packages. A heat seal is then placed across the structures in the transverse direction of the thermoplastic structures below the product filling tubes to form a pouch. Product is then delivered into the individual pouches and the delivery tubes are then extracted from the pouches. A final heat seal is disposed to seal the tops of the individual pouches. Heat seals, however, typically require heat seal zones free of contaminants and/or wrinkles to prevent weak heat seals from forming. Weak heat seals can cause a loss of a flowable product since a flowable product contained in packages having weak heat seals may spill from the packages if the heat seals break or otherwise delaminate. Moreover, packages having weak heat seals may lose their oxygen or moisture barrier characteristics.
Typically, to increase the sealability of packages for flowable products, a high melt flow thermoplastic material is used as the heat sealant layer. However, high melt flow materials tend to increase the tear resistance of the packages, thereby making it more difficult to open by using tearing forces.
A need, therefore, exists for a multilayer heat sealant structure having improved tearability, while also being easily heat sealed, even in the presence of contaminants and/or wrinkles. Moreover, a need exists for packages made from the multilayer heat sealant structure to contain flowable products therein, such as, for example, condiments and the like. In addition, a need exists for structures, packages and methods of making the same that solve the problems associated with prior art structures and packages for flowable products, such as, for example, condiments or the like.